100 CAPS | 500 MG Product No. 00148

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L-Tyrosine has many and varied functions. It is needed to make epinephrine, norepinephrine and dopamine; all of which work to regulate mood. It aids in the production of melanin, in the regulation of the adrenal, thyroid and pituitary glands, and is involved in the synthesis of enkephalins, the body’s natural pain relievers. L-Tyrosine should not be used with MAO inhibitors. *

  • Benefits overall metabolism*
  • Provides building block for energizing neurotransmitters*
  • Promotes focus and mental clarity*


* These statements have not been evaluated by the Food & Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.



Product Code: 00148           Capsules per Bottle: 100


Each size 00 vegetarian capsule contains:


Vitamin B-6 (as Pyridoxine HCI)

10 mg


500 mg

  Other ingredients: L-leucine.


What is L-Tyrosine?

Tyrosine is a non-essential amino acid, but natural production may be affected by the intake of its precursor, essential amino acid, phenylalanine. The metabolism of tyrosine is a precursor for the production of catecholamines (epinephrine, norepinephrine, and dopamine), all of which help to regulate mood, focus, and cognitive function. Tyrosine is also a component of enkephalins (or endorphins), which are natural pain relievers.

Activated vitamin B-6 has been added as an aid to amino acid metabolism.


How does L-Tyrosine Work?

In the body, L-tyrosine is converted into the compound L-DOPA by tyrosine hydroxylase. L-DOPA is then decarboxylated into dopamine, which can be oxidized into norepinephrine and then converted to epinephrine depending on the body’s need for each of these neurotransmitters[1]. Although technically a “non-essential” amino acid, supplementation of tyrosine has been shown to increase both plasma tyrosine and brain dopamine production [2]. 

As a precursor for the production of both dopamine and norepinephrine, tyrosine supplementation may improve cognitive flexibility and counteract or reverse cognitive decline through the rescue of neurotransmitter function [3,4]. Tyrosine’s support of cognition may be most pronounced in acutely stressful situations such as extreme cold, high altitude, and sleep deprivation [3,4]. It may also help to protect against neurological decline in elderly patients with dementia. As dementia progresses, catecholamine levels decrease, and catecholamines have an antioxidant effect in the brain, which may, in fact, be neuroprotective [5].

L-tyrosine is also a component of enkephalins (or endorphins), natural pain relievers that activate pathways resulting in simultaneous dopamine release and locomotor activation [6]. The role of L-tyrosine is essential to the hypothalamo-pituitary-adrenocortical (HPA) axis, which controls adrenal glucocorticoid stress response, as well as regulation of the adrenal, thyroid, and pituitary glands [7].


What are the Suggested Uses for L-Tyrosine?

  • As a precursor to energizing neurotransmitters, L-tyrosine promotes a positive mood, focus, and mental clarity*
  • Plays a role in the body’s regulation of and reaction to stress as a component of endorphin production and critical to the hypothalamo-pituitary-adrenocortical (HPA) axis.


Source Materials: Pyridoxine HCl is made by chemical synthesis. L-tyrosine is derived from hydrolyzed corn protein. L-leucine is made by fermentation. Cellulose for capsules is derived from softwood tree pulp. All ingredients are vegan and non-GMO.


Allergens:  According to information provided by our suppliers, these capsules are free of the eight major allergens as identified by the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA): Wheat (gluten), eggs, milk, soybeans, shellfish, fish, peanuts, tree nuts.


Recommendations: Use as directed by a healthcare professional.


Precautions: L-Tyrosine should not be used with MAO inhibitors. Pregnant or lactating women and individuals taking prescription medications should consult with a healthcare professional before taking any supplement.



  1. Nakashima A, et al. Role of N-terminus of tyrosine hydroxylase in the biosynthesis of catecholamines. J Neural Transm. (2009)
  2. Colzato, Lorenza S., et al. "Eating to stop: tyrosine supplementation enhances inhibitory control but not response execution." Neuropsychologia 62 (2014): 398-402.
  3. Jongkees, Bryant J., et al. "Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands—a review." Journal of psychiatric research 70 (2015): 50-57.
  4. Neri DF, et al. The effects of tyrosine on cognitive performance during extended wakefulness. Aviat Space Environ Med. (1995)
  5. Jodko K, Litwinienko G. Oxidative stress in the neurodegenerative diseases--potential antioxidant activity of catecholamines. Postepy Biochem. (2010)
  6. Sesack, S. R., and V. M. Pickel. "Dual ultrastructural localization of enkephalin and tyrosine hydroxylase immunoreactivity in the rat ventral tegmental area: multiple substrates for opiate-dopamine interactions." Journal of Neuroscience 12.4 (1992): 1335-1350.
  7. Herman, James P., Chantai M-F. Prewitt, and William E. Cullinan. "Neuronal circuit regulation of the hypothalamo-pituitary-adrenocortical stress axis." Critical Reviews™ in Neurobiology 10.3-4 (1996).
  8. Riley, P. A. "Melanin." The international journal of biochemistry & cell biology 29.11 (1997): 1235-1239.



* These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.


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